Part II: The diesel police have spoken, the deadline for cleaner on-highway engines is here and while the process has been chaotic, the sky has not fallen.
As of October 1, if you buy on-highway trucks – haul trucks for your equipment, vocational trucks such as dump trucks or cement mixers or any road-licensed diesel-powered vehicle – the Environmental Protection Agency has good news for you. Your new truck or engine is now contributing less air pollution to the environment.
The downside, though, has many truck and equipment fleet customers concerned. The new low-emissions engines are going to cost more. The range of engines available has been reduced. And the new engine technology, while lab certified, has yet to log a substantial number of hours in the field.
How it all got started
The drive to make on-highway diesel truck engines emit less air pollution started when the EPA established a series of deadlines and emissions limits, primarily emissions of oxides of nitrogen (NOx), that manufacturers had to meet. Manufacturers met the first deadlines easily enough with engine refinements and electronic controls combined with a drastic reduction in the sulfur levels of on-highway diesel fuel. Then they went back to work looking for ways to meet the next emissions deadline, which was due in 2004.
But along the way, the EPA accused six engine makers – Caterpillar, Cummins, Detroit Diesel, Mack, Navistar and Volvo – of using what it called “defeat devices” on their engines. The EPA claimed these defeat devices enabled the engines to meet emissions regulations under normal operating conditions, but then circumvented the pollution controls whenever the engine was straining or working under a heavy load.
As a result, each of the manufacturers except Navistar (manufacturer of International trucks and engines) signed consent decrees with the EPA in 1998 stating they would have their engines ready for certification 14 months ahead of schedule – on October 1, 2002 (the so called “pull ahead” deadline) rather than January 1, 2004. Thus ensued a mad dash that’s still not finished as the six engine makers began to try to figure out how they were going to meet the emissions limits in such a short period of time.
Cooled EGR establishes an early lead
At the time the consent decrees were signed the general consensus was that EGR (Exhaust Gas Recirculation) technology would provide the necessary emissions reductions. EGR has been used in automobiles since the mid-1970s and reroutes the engine’s exhaust gas back into the combustion chamber where it lowers the combustion temperature and reduces the amount of NOx formed. Together with further engine refinements, EGR seemed to hold the most promise as a solution.
Most of the manufacturers used a type of EGR called cooled EGR. “Cooling the EGR is good for the fuel economy,” says Zack Ellison at Cummins Engine. “We put competitive teams of engineers together to come up with different ideas to meet the emission requirements. We tried cooled EGR, uncooled EGR, no EGR, timing and pilot injection and about every variable and combinations of those variables and then had a runoff. Cooled EGR came out head and shoulders above the rest.”
But there were engineering challenges with EGR. Driving down the NOx levels meant that soot levels rose. The recirculated gas also created a more acidic environment in the engine. And the EGR engines ran hotter. To a large extent these problems were eliminated or reduced by the introduction of the new high-performance API-CI4 oils that came on line this year (see “The EPA and your fleet, Part I” in the September issue of Equipment World).
Weighing the two-engine scenario
But the heat issue bothered Caterpillar engineers more than the rest. Cat wanted a low emissions engine technology that would work in both on-highway and off-highway applications since of the six manufacturers that signed consent decrees, Caterpillar had the largest share of off-highway engines. And while heat is a challenge for on-highway trucks, it is a major obstacle for large earthmoving equipment.
“With EGR, if you have a truck going down the road at 70 miles per hour, then cooling is not as much of an issue,” says Carl Volz, Caterpillar corporate public affairs. “But if you have a track-type tractor, you either have to have a radiator the size of Texas or you look for some other technology. Our competitors don’t have to worry as much about off highway, but our customers need a solution for both.”
And even though the next big cuts in emissions from off-road diesel engines were not due for several years, Caterpillar, having spent nearly a half-billion dollars on its research, did not want to develop two different engines, one for on-highway trucks and one for off-highway equipment.
Cat goes its own way with ACERT
In March 2001 Caterpillar broke away from the pack and announced it was abandoning EGR in favor of a proprietary technology it labeled ACERT or Advanced Combustion Emissions Reductions Technology. In doing so the company also said ACERT would be its solution for the pending on-highway emissions standards as well as the final stages of Tier 2 off-highway engine emission standards that take effect in 2004 and the first stages of Tier 3 off-highway standards in 2005. (For off-road diesels the EPA established a “Tier” system whereby emissions reductions are phased in by horsepower – the more powerful the engine, the earlier it’s due for reductions. For on-road engines the regulations cover all horsepower ranges in one fell swoop.)
“ACERT burns more emissions at the point of combustion,” says Volz. “We’ve been able to manipulate to the nanosecond the spray from the fuel injection assisted by our Cat electronics products we have on the engine.”
Tana Utley, director of engineering at Caterpillar’s Mossville engine center, says the electronics are the key to controlling combustion. “We try to get everything we can out of the cylinder, to have the lowest possible in-cylinder emissions and recover as much energy from the air stream exhaust gasses as we can and make the best use of turbo-charging to get the right air-fuel ratio,” she says. “Then whatever emissions we aren’t able to clean up in the cylinder we pick up in the aftertreatment.”
Not going to be rushed
But given the shortened deadline imposed by the consent decrees, Caterpillar announced this summer that its first ACERT on-highway engine would not be ready until early next year. Instead the company is offering what it calls a “bridge engine,” which offers improved emissions levels and for which Caterpillar is prepared to pay whatever fines or penalties the EPA decides to impose.
“The bridge engine is based on today’s engine and there are not a tremendous number of changes between today’s engine and the bridge engine,” Utley says. “We are making a few of them already, but the lion’s share of the engines we are making right now fit the older emissions level. The changes in the bridge engines are mostly in the aftertreatment end of things and will be transparent to the end user.” Cat’s strategy is to roll out the first ACERT engine, a C-9 model, in early 2003 and then bring out progressively larger ACERT engines over the following months.
The fall lineup in engines
As of the October 1 pull ahead dates, expect to see the following engines offered:
· Caterpillar’s bridge engines will be offered in some GM and Chevy vocational trucks and Freightliner, Sterling, Western Star, Paccar, Kenworth, Peterbilt and International highway trucks.
· Cummins submitted its first Tier II engine, the 15-liter ISX model on April 2 and has since submitted two more models, the 5.9-liter ISB and 10.8-liter ISM engines. The ISX and ISB have both been certified. Cummins’ engines can be speced for Ford vocational trucks and Freightliner, Sterling, Western Star, Mack, Peterbilt, Paccar, Kenworth and Volvo highway trucks.
· Detroit Diesel submitted its on-highway Series 60 engines for certification in August and its Series 50 engines in September. Both use cooled EGR and variable geometry turbochargers. The Series 60 comes in a 12.7-liter and 14-liter version and in power ranges from 300 to 575 horsepower. The Series 50 is the four-cylinder version of Series 60 and comes in power ratings from 250 to 320 horsepower. Coincidentally, the Series 50 engine has been using EGR since 2000. The two engines will be made available for Freightliner, Sterling and Western Star trucks.
· Mack comes to the ballgame with two new Application Specific Engine Technology (or ASET) engines. For the steady operating environment and fuel economy needs of highway haul trucks Mack is offering a standard cooled EGR design for its Vision and CH Series. But for the vocation trucks in which fuel economy is not such a critical issue, Mack has designed what it calls an Internal-EGR (or I-EGR) engine. These use a new camshaft design and advances in the valve system to retain a certain amount of gas in the cylinder for secondary combustion. The company says this design more closely matches the stop-and-start characteristics and harsh operating environments of vocation trucks. I-EGR will go into the new Mack Granite Series and Mack RD6, MR, LE, DM and RB models. Some Cummins engines will also be available for Mack trucks.
· Volvo submitted its 12-liter VED engines in power ratings from 365 to 435 horsepower and will have its 465- horsepower version ready in early 2003. Volvo engines use what the company calls Volvo Variable Pulse (V-pulse) technology, which harnesses the exhaust stream’s naturally occurring pulsations to recirculate up to 30 percent of the combustion by-product back into the combustion chamber.
The good, the bad and the ugly
Drivers who have run highway trucks with the new EGR engines report good results. “The feedback we’ve gotten after 6 million test miles is that the drivers love it,” Ellison says of Cummins’ research. “The throttle response, the drivability, the low rpm torque capability that come from having a variable geometry turbocharger is pretty fantastic. It also improves their compression brake capability by about 100 horsepower over what they’ve had in the past.”
The main concerns with the October EGR engines were the fuel economy, price and long-term durability. Most experts are pegging the fuel efficiency of EGR-based engines at 2 to 5 percent below that of the non-EGR engines. Price increases per engine are predicted to run in the $3,000 to $5,000 range. As for long-term viability, that’s anybody’s guess. Cummins has tried to take some of the uncertainty out of this concern by issuing an “uptime guarantee.” Pre-buying also became an issue this summer when the EPA became concerned that some companies were encouraging customers to buy non-EGR engines before the deadline. It sent out a letter asking manufacturers about promotional activities. But the inquiry failed to find any wrongdoing and fizzled out.
Factory slowdowns and layoffs
Another unfortunate side effect of this turmoil in the diesel engine industry is the loss of jobs that has resulted. As orders for new engines began to drop off this summer Caterpillar said it would lay off about 470 full-time and 290 part-time workers. At Detroit Diesel, Tom Freiwald, senior vice president of marketing, says on-highway engine production is expected to drop from about 250 engines a day to 50 or 60 engines a day and that would result in layoffs of some 500 regular and 200 temporary employees.
With the scramble to get the new technology in place before the October 1 deadline, plenty of controversy has been generated about what effect EGR will have on engines, truck sales and the industry as a whole. Off the record, manufacturers complain the pull-ahead deadline made it difficult to get enough engines into the hands of their big customers (the freight companies and highway truck fleet owners) for thorough evaluations. Truck manufacturers in some cases had just weeks to figure out how to fit the new engines into their vehicles. And when the big trucking companies and the American Trucking Association appealed to the courts for deadline extensions they tended to paint a worst-case scenario. Rumors flew hot and fast and a perception emerged that things were worse than they actually were.
Here to stay
But the facts are the engines are here to stay, prices are up and sales are down for now, but engine buyers will eventually have to start coming back. The highway truck business is going to feel the biggest impact, but the fallout for construction contractors who own a few vocational or haul trucks will be much less. The sky may be thick with regulatory fog, but it’s not going to fall anytime soon.
Off-road engines the next target
The next emissions regulations for on-highway trucks don’t kick in until 2007, but the manufacturers that signed the original consent decrees have also agreed to a Tier 3 deadline of 2005 for certain categories of diesel-powered off-road equipment. But the EPA has put the specific emissions targets on hold until it can figure out if, how and when low-sulfur fuels may impact the emissions scenario.
So the dates are set for the next round of off-road emissions deadlines, but the manufacturers can’t do much until the diesel fuel sulfur rules are written and the EPA decides how much NOx or particulate matter will be allowed in the next generation of engines. The EPA has also said it is considering incentives for early adoption of emission control technologies and emission reduction credits as part of the Tier III regulatory package.
Stay tuned.
